How to set/get NIC speed and duplex:


  1. Pick an interface to query or configure - This example specifies hme0
    2. # ndd -set /dev/hme instance 0
  2. Display current duplex for the selected interface:
    3. # ndd -get /dev/hme link_mode
  3. Display current speed for the selected interface:
    4. # ndd -get /dev/hme link_speed
  4. Turn autonegotiation off using:
    5. # ndd -set /dev/hme adv_autoneg_cap 0
  5. Change the 'advertised capabilities' of the interface:
    6. # ndd -set /dev/hme adv_100hdx_cap 0
# ndd -set /dev/hme adv_100fdx_cap 1

The example above sets the card to advertise ONLY 100MBps Full Duplex